Inductive electric heaters are in general use in several fields, such as medicine and printing. A heating slug of metal such as iron or steel is placed within proximity to an alternating electrical field. The alternating field induces currents within the slug, causing the slug to heat.
This type of electric heater has been used in a variety of different applications. For example, the arrangement is used in fluid heaters, such as the one shown in U.S. Pat. No. 6,118,111, entitled “Fluid Heater” and issued to Nigel Brent Price et al. U.S. Pat. No. 4,032,740 entitled “Two-level temperature control for induction heating” and issued to Eugene Mittelmann shows an induction heating apparatus for heating work pieces.
Inductive heating systems allow the heating of objects without providing electric current directly to the object or by running wires into the heating element, thereby allowing some degree of isolation of the heating slug from the rest of circuitry. However, such systems fail to provide sufficiently fine control of the temperature for some applications, and thereby limit their utility.
Thus, an improved induction heating system is highly desirable.